The transmission of real-time video over wired/wireless channels is increasingly desirable. The transmission system should provide a maximum visual quality for channels with limited capacity while being implemented in devices with limited memory size (where the total memory size of the transmitter is less than the size of the input picture). An image/video coding standard known as JPEG 2000 is a good solution for this task because it provides rate control with a high accuracy level. (ITU-T and ISO/IEC JTC 1, JPEG 2000 Image Coding System: Core Coding System, ITU-T Recommendation T.800 and ISO/IEC 15444-1, JPEG 2000 Part 1, 2000.)
The use of JPEG 2000 may be problematic, however. Where the memory size is restricted (the normal case), the input picture is preferably split into small fragments (tiles), such that each tile may be compressed separately. The original JPEG 2000 rate-control implementation provides approximately an equal bit-size for each compressed tile. But visual quality of the decoded tiles may be rather different. For example, in some implementations, the quality of the reconstructed image may be inconsistent. For example, in the image 50 of FIG. 4, some decoded tiles have a “good” visual quality, while others have a “very bad” visual quality.
Thus, there is a need for a video compression and transmission scheme to overcome the shortcomings of the prior art.